Anytime a VIP gets caught with his (or her) pants down -- Arnold Schwarzenegger or Anthony Weiner, for example -- you can almost hear the collective "huh?" around the nation's water coolers, on its Twitter feeds and shared over its backyard fences.

What in the heck were those guys thinking? Where were they when John Edwards, Eliot Spitzer, Bill Clinton and so many others crashed and burned? Why wasn't the very real risk of shame and humiliation enough to stop them cold? More than 2,000 years ago Socrates asserted in Plato's "Phaedrus" that two horses contend for our souls -- one, unruly, passionate and constantly pulling in the direction of pleasure, and the other restrained, dutiful, obedient and governed by a sense of shame. But a set of studies I conducted with two other researchers at the University of Southern California Marshall School of Business suggests that Socrates was wrong, at least about Horse No. 2. Humans may be pulled hard toward pleasure, but shame isn't the countervailing force that reins us in.

In fact, the more we anticipate wagging fingers, public pillory and guilt, the worse we're likely to do when it comes to self-control. If we focus on the pride that comes from good behavior, we make better choices. By far.

The proof is in the devil's food. In one of our studies, we put three groups of subjects alone in a room with a very large piece of chocolate cake, the utensils to devour it and water. We told them they could eat as much or as little cake as they wished. But first, the members of one group were instructed to focus on the pride they would feel if they resisted the cake. Those in the second group were told to imagine the shame they would feel if they ate it, and the final (control) group was simply let loose, with no instructions at all.

We discovered that the study subjects who anticipated pride at resisting the cake consumed far less than those who focused on the shame of succumbing. They also ate less than the control group. In other words, when it comes to self-regulation, anticipated pride outperformed anticipated shame as well as unconsidered, heedless consumption.

What would make anticipating pride so much better than anticipating shame in controlling temptation? One reason is that pride focuses attention on the self (not the cake) and on success rather than failure. Shame, on the other hand, emphasizes the opposite; it focuses attention on the object of desire and the act of succumbing, making resistance harder to pull off. Simply put, anticipating pride makes us feel good, and anticipating shame makes us feel bad.

We know from prior research that we're better able to resist temptation when we feel good, not bad. Our research also indicated that not all bad feelings are equal when it comes to undermining self-control. For example, when we asked subjects to anticipate guilt instead of shame, it made them eat more cake. Guilt, it turns out, carries a triple whammy: It concentrates thoughts on the temptation rather than on self-control; it makes you generally feel bad, weakening resistance; and it heightens the expected pleasure from being bad, which makes the temptation more tempting.

Can any of these results prevent another politician from a precipitous fall from grace? Maybe -- if they work at it.

For starters, our studies suggest that heaping humiliation and punishment on the Anthony Weiners of the world may not so much prevent the next outbreak of idiocy as encourage it. Instead, we have to concentrate on cueing the good feelings that come from doing good.

For those who want to resist chocolate cake, it could mean pasting a picture of your slimmest self on the pantry door. For those of you who made wedding vows, it could mean fending off seduction by imagining your next anniversary with the woman or man to whom you promised everlasting fidelity.

My colleagues and I studied chocolate cake consumption as a matter of business. What we found could help groups like insurance companies or healthcare providers develop strategies to encourage self-control when it comes to smoking, drinking or getting the proper amount of exercise. But the lessons apply to anyone faced with temptation.

Remember that anticipated shame won't help, and anticipated guilt will only make it easier to succumb. Instead, think about the positive effects of doing the right thing. And you probably will.

Deborah MacInnis is the vice dean for research and strategy, and a professor of business administration and marketing at the University of Southern California. Her co-authored studies on self-control and chocolate cake were published in the Journal of Consumer Psychology and Advances in Consumer Research. She wrote this for the Los Angeles Times.